Shizuka Shirogane: the 1000 IQ Orphaned Tomgirl Detective of Truth
by KingJGamer
Summary: Shizuka was taken as a baby and left of the doorstep of the Shirogane's. Stuff happens. (Fem!Izuku) (Also a One-Shot, If anyone want's to adopt this, plz PM me)


_Ok, I seem to have a wild imagination, so let's get this one out… god… four fanfics… I'm crazy. Anyways, I don't own anything, My Hero Academia is owned by Kohei Horikoshi and Persona by Atlus… I'm lazy to never do disclaimers all that often._

* * *

 _In a world with quirks and heroes, there was a little girl who was born. She was immediately taken away by a strange force, a man who has her destiny in mind. It was a former worker of the Velvet Room, and he decided to fulfill a greater fate for her. So he kidnapped the baby, went to another dimension, and left her on the doorstep of the Shirogane's. They just had their kid a few months back, a girl named Naoto. But before that… Shizuka's original parent's? They lost their shit, the dad left, and the mom was left heartbroken and… well broken. She had to go to many suicide prevention people, oh… and if you have thoughts of suicide in real life… you should find help… in counselors or anonymous groups… this is being made in September 10th… this section at least._

 _Anyways back to the story, Shizuka was then adopted by Naoto's parents when they couldn't find her actual family. They then raised her like their daughter, and she was very, very tomboyish. Very like her sister, who was naturally boyish. The two of them grew up and they both became the detective Prince and Princess. Being intelligent and already helping in police investigations. Shizuka didn't really like being called a princess by any stretch of the means. So they changed it to Detective Prince Duo, Izuka was very much a tomboy and her sister… just took the mantle of a boy to not regard sexism on the police force, she stopped people who harassed Shizuka. Then they went to Inaba._

 _Let's just skip to the dungeon of the sisters._

* * *

"LEAVE THE FACILITY IMMEDIATELY!" The Investigation team ignored that and continued to walk down the corridors. They were cutting down shadows left and right. With the danger of a body alteration, they needed to get to the bottom. But when they got there… Naoto was having a peaceful conversation with her shadow… who was crying. And Shizuka's shadow was having a joyous face talking with her physical self. The reason for Shizuka's, she didn't have much in the way of things she denied to herself. Other than a small inferiority complex she's working on getting rid of, a need for more power to help people, and the pain of the harassment on the police force.

" _Hey… do you ever wonder about your real parents?"_ This is the conversation of Shizuka and her shadow. She learned early on that she was taken in by the grandfather after the foster parents died in an accident, she had to cry into Naoto for three days.

"...If i'm being honest… I question that myself… If I go on a look for them, then I miss the chance to bring so many people to justice. But if I don't, then I don't know the answer to my biggest mystery…"

" _Quite the dilemma you have there… but you never did have the power to find them."_ Shizuka then became quiet after that. " _You never are strong enough to help, you only point people in the direction that they want to. But you always stop to help those you can…"_

She remembered those times she had to put herself on the gurry to try and help those in the line of fire and dying. She saved many, but not all. "Yeah… but I still failed to help those next to me… it hurts. Along with… other things"

" _The harassment and the being in the shadow of Naoto do hurt don't they…"_

"Wait, how do you know all this?"

" _Because I am you in this world, I am what you don't want about yourself. The part of you you denie. But you are a rare case among the masses, you don't deny anything about yourself. You keep it to yourself… but you always have yourself to admit to…"_ At that moment, Naoto's shadow started to attack the Investigation team. Shizuka turned to see friend she made little but there connections with being attacked by the shadow of her sister.

" _You want to help them, don't you?"_ Izuka nodded, " _Good, then accept my power, and become stronger."_ The shadow then turned into a card of the Justice Arcana. She then knew what to do. Breaking the card, her persona came out.

"AZRAEL!" The card shattered and revealed a being with a human like face, with a female figure, and blackish purplish hair. Wearing a witch-like hat, holding a scythe (with two blades and a skull attached to the end), and an outfit of a tight suit with a v-neck down the chest connecting to three red buttons. (Ok, I googled a redesign for Azrael (in Azrael Persona google search) and came across this picture for it. I decided to use it. I couldn't find the original artist, but it was good enough for me. If you come across it, you will know.) It had a kind of fairy like appearance, but it didn't matter to Shizuka. All she cared about was saving her sister from dying.

* * *

 _She then helped save Naoto and have her realize her true self. She then helped and brought Tohru Adachi in and solve the mystery of the murdures. Then the Midnight chanel reopened and the plot of Persona 4 Arena Ultimax (or something) happened. If you want to know her look, she has a beanie, a school blazer open, and the green black hair at shoulders length and slightly over one eye. But this story… something different happened..._

* * *

Shizuka and Labrys are fighting Shadow Labrys and Sho. The clash of the swords of Sho, the axes of the robot girls, and the bullets being shot with Shizuka's sword and gun combo. Sho then decided to use a small amount of the persona shards to use a more… wild power. And in a flash, and a strike, Shizuka was gone in a flash.

"SHIZUKA!" Labrys yelled with sadness, and turned to the two remaining, but they were gone.

 **Meanwhile**

Yu Narukami and Tohru Adachi were fighting. Yu goes in for a low strike while Adachi goes for an overhead. Adachi strikes first and sends the Persona 4 protagonist flying back, then Yu retalied with a zio. The force of the lighting sends Adachi flying backwards, and into a strange pool. He remembers the pool for being 'The TV to another world, with no way back' and falls into it. Immediately the pool reacts with persona shards he had and was gone in a flash. Yu noticed this strange thing happening, but decided to look for their friends instead of looking for Adachi.

 _ **Final match of the U.A. Sports festival**_

The finalists were Katsuki Bakugo and Shoto Todoroki.

"AT LAST, WE'VE ARRIVED! THE BEST OF THE BEST AMONG U.A.'S FIRST-YEARS WILL BE DECIDED! IT'S THE FINAL MATCH… SHOTO VS KATSUKI!" The crowd was bursting with excitement at the final prospects of the battle. An incredible clash of explosions and ice.

"NOW-" but before they finished the start, two flashes and bangs happened on the stage. Everyone covered their eyes, thinking it was a villain attack, the two contestants ready their quirks. And Midnight and All Might are at the seen, ready to fight. But what they saw just made them confused. The two people at the stage was a normal looking man with a gun, looking like he was waking up from what knocked him out. The other was a tomboy girl with a hat on and looking only slightly older than the students holding a gun in one hand and holding a sword (imagine Linne's big blade from Under Night In-Birth, but more manageable).

The two of them woke up soon after the confusion started. "Gah… wah-" Shizuka then remembered what happened, she was fighting Sho and Shadow Labrys with Labrys when Sho used some weird power on her. Looking around, she saw that it wasn't anything like the normal areas of the TV world. She then noticed another figure across from her, and immediately got into a fighting stance.

"My oh my… if it isn't the junior detective. I never expected you to be here."

"Save it Adachi, how did you escape?" Much of the crowd confusion. Thankfully the heroes had the students leave arena, so no one would get in the way of what happens next.

"It's simple really, the Minazuki kid broke me into 'his' world to help him. It was slightly fun to see you guys. Unfortunately my 'boss' didn't give much in the way of examples. But honestly, could care less… that's just how life is. Now i'm here, and i'm going to see if you can catch me all by your little lonesome. It might take away some of my boredom."

Shizuka then retorted, "Well then, I will send you back."

The two of them take stances, and charge in to beat the other down.

"AZRAEL!/MAGATSU-IZANAGI!"

Summoning their Persona's, the two clash. Immediately sparks fly at the four beings clash. The energy sends all of them back, but Shizuka recovers quicker and goes it for a low attack. It hits and Shizuka uses a quick combo of sword slashes and finishes off with a gun blast, inflicting sukunda. See, Azrael has a focus on support skills, buffing and debuffing. She also has Light and Darkness skills (Though few) and one almighty attack and one unique physical attack. Shizuka uses her almighty attack to send people crashing into the ground and walls and her light and darkness attacks like her sister, but reversed. But her unique physical attack, that is something for a finisher… she has a lower grade version for a normal super move.

Being at a disadvantage with the slowdown, he uses Zio to try and play keep away while he waits for it to wear off. It works and he charges in for a grab, she breaks it, but was unprepared for the follow up with aggressive Persona strikes and attacks from Adachi. These strikes give Shizuka a lot of SP, but no opening as she was trying to not get hit. The strikes that he did really hurt and She didn't know if she could survive another raw strike like that.

Thankfully, she got an opening when Adachi whiffed a heavy gun strike. This gives her an opening to stager with a scythe strike from her Person, then with a finisher. She slashes Adachi a few times, sending him into the air.

"Let judgment be passed!"

Bringing out two heavy sniper rifles (she got out of practically nowhere) and having her Persona create two elemental circles or Light and Darkness. Shooting them, and sending him flying back down from the force of the shots.

"So the truth can be found!"

Her Persona then used her final attack,

"JUDGEMENT REAP!"

And slashes Adachi with the scythe, finishing the fight with one decisive strike. The force could definitely cut someone in half, but didn't as that would meen she couldn't bring him in to the police again.

 **Meanwhile, at the same time…ish (time dilation is weird), Persona world**

Naoto wasn't very happy. In fact, when she heard from Labrys of her disappearance and probably being dead, she denied it and started to tear up. She help those back while she went on to look for Sho and Shadow Labrys. When they found senpai Yu, he informed them of the strange thing that happened with Adachi. Not wanting to believe that Shizuka was gone, she asked Yu if they could go find the other foes they had to worry about. Yu agreed and then ran to find them. They also found the crew of Persona 3 along the way and joined up with them.

When they found the two, Sho was taken over by Hinokagutsuchi. When the takeover was over, Minazuki had a word with Naoto.

"Where is Shizuka? Tell me!" Naoto was being more emotional and a bit more emotional, and was walking over to get the information.

"Hmph… like I would know, she was probably sent to the same place as that damn officer."

"Adachi? Where did he go?"

"Who know, probably dead at this point." And at the mention of Shizuka being dead, she snaps, going in to attack with rage. Then a fight incurs with Naoto striking first. Landing a blow, and knocking Minazuki away. She then brought out her pistol and shot at him. He avoids the shots and decided to use the power of the Persona shards to teleport her like the sister. At that moment, his hands started to glow. Yu recognize this as it was the same light that appeared to take Adachi.

"Get back! IZANAGI!" Summoning his persona to clash the attack, it creates a shockwave and in an instant, they are all gone.

 **The stadium for the U.A. tournament**

"Young girl!" Shizuka turned to see a buff man wearing a strange costume and a woman in a BDSM costume. She gives them a blank stare and just shrugs, she has seen stranger.

"I should ask why you fought that man… but I also wanted to know why you used your quirk in public?" The question stuck with her, what did he mean by that? She also looked around to see that they weren't anywhere in the other world, what with the amount of people and lack of shadows.

"Heh… looks like another weirdo shows up…" Adachi says weakly, trying to sit up from the damage that Shizuka did to him.

"Man… I really hope this isn't the shit we call home… that would suck having costumed weirdos out in public."

"Adachi… you're supposed to be in jail… did Sho really do all that to break you out?"

"Nah… I just did it to try and have some fun, I do want to go back to my original cell tho." Then the strange man and woman brought out a pair of handcuffs. But Adachi shook his head when they did.

"Nah… It wouldn't be the same if I didn't get turned in by one of the investigation team. Besides, I was going back to my cell after all this is over." The heroes didn't believe that and went in to arrest him anyways.

But to interrupt with dramatic timing, a flash shown and another group appeared. This one consisting of a lot of teens, a few young adults, and two boys who look exactly the same and with the same dark aura, tho one's was greater for slightly obvious reasons.

"Big sis!" Shizuka exclaimed with joy when she saw her sister Naoto with Senpai Yu and the gang. She charged in at them to hug her, but was stopped when the buff guy grabbed her by the collar.

"Now now… we still need to take-" But at that moment, Naoto kicked All Might's hand (oh no, I got lazy and just used his hero identity) and shot his arm, fighting game logic dictated that shouldn't cause it to bleed because reasons, but it was an actual shot, it hurt like a b****.

"Get your hands away from her!" Naoto snapped, she didn't want to lose her sister. Not after what she felt with her parents. She then looked and Shizuka, and hugged her and cried. Shizuka had to comfort her. While all this was happening, the investigation team were having sweat drops and some sweating bullets.

"Huh… does anyone else think it's weird that Naoto is being this emotional?" This was Kanji asking a legitimate question.

"Yes… let's hope we don't piss her off to the point to do that right?" Yosuke asked Teddie.

"Yep… Naoto is scary when this happens…"

Aigis then asked a question out of confusion. "Is this the 'Love between sisters'?"

"Yeah probably…" Labrys responded, "Unless your talking about the next level kind of relationship between sisters. In which case… probably not."

Yukari then gave them the blank stare, "This doesn't have anything to do with incest, that just be weird."

"And the fact that we're surrounded by civilians probably means that we're not in the other world…" This was the head of the Kijiro group, Mitsuru Kijiro.

Junpei and Akihiko then realized something at that moment. "Guys… What happened to that Minazuki kid?" They turned to see… Sho spouting rage and that he was going to destroy this world as well. While they also saw Minazuki (the possessed form of him) contemplating opening a portal, he then spewed something about destroying this world first as a test for his power. Then they both got shot by Adachi, now in an upright position, with a slightly pissed of expression.

"What did you guys just forget about me?" Then at that moment, some of the school faculty came out to stop all of them, and get All Might medical attention for a moment.

"All of you, stop right there! You need to come in for questioning for the police to interrogate!"

"Oh please… I should just destroy that first!" Then Minazuki attacked the Heroes while Sho was attacking… everyone in sight. Everyone was all staring, and wondering one thing. Aigis then spoke what everyone was thinking.

"How did we let this happen?"

"No sis, I think the question we need to ask is… 'how did we not notice this sooner?'"

Junpei and Yosuke then charged Sho, in an attempt to slow him down… but they were sent flying into Minazuki. Minazuki, on the other hand, was dealing with Shizuka, Cementoss, and Naoto. They were holding him back pretty well, until he shot out a wave of darkness that shot everyone back. Yu then made a split decision, and so did the cast of Persona 3 Mitsuru did her orders first.

"Labrys, Aigis, Ken, go help with Minazuki. Junpei, Akihiko, Yukari, we need to stop Sho." Yu followed up.

"Kanji, Yukiko, you go help Shizuka and Naoto. Everyone else, let's go stop Sho!"

And then, all hell broke loose.

Kanji and Yukiko use fire and lightning to cover their entrance, this allowed Shizuka to use a vorpal blade and shatter Minazuki's Persona. Then the group of people charged from her, but Shizuka was going to check Adachi. But then Minazuki tried to escape using a portal.

"Damn basterds, looks like I'll leave you here to rot."

"Oh no you don't!"

Shizuka and Adachi (still injured) strike down Minazuki and hold him back.

"Adachi, go now!" Adachi is a bit confused at this, she considered him an enemy.

"Oh come on, you want to be in your cell, right?" Adachi just smiled at that.

"Ok then, don't let anyone die!" He then jumped through the portal as it was closing up.

"Damn it… DAMN IT!" Minazuki then used his persona to blast everywhere with a smokescreen. He jumped out of the stadium, and Sho followed behind and ran in a different direction to leave.

"Damn, he got away!" Junpei punched the ground in rage.

"Don't worry, we'll get another shot. For now… how did we not notice the people around us?" They all then took a look around to see… ordinary people, and no shadows.

"You there, I must say, good work for helping with the villain, but I must have you placed under arrest." Yu and Mitsuru asked if they could go to a more quiet place, they agreed, and they explained the entire situation to the heroes.

"Wow… that sounds so ridiculous it's believable."

"Yeah, because it's the truth"

"It is true, both the existence of me and my sister an atain to that"

"Yeah, like that-" Then Labrys detached her arm, proving she was a robot. They then got into peace talks, having some people act as substitute teachers for the time they will be here, and a way to make up for messing up the U.A. tournament.

"Hm… could we have the finalist fight two of our's?"

"That be a good idea, but who would be fighting?"

And after some debate, it was decided that Shizuka and Labrys who would fight. Labrys felt a bit bad after failing in a way, and Naoto didn't hold it against her.

"ALRIGHT, APOLOGIES FOR THE INTERRUPTION, BUT LET'S GIVE YOU AN APOLOGY THROUGH THE BATTLE OF FISTS AND POWERS! WE HAVE A TAG MATCH BETWEEN THE FINALIST OF OUR TOURNAMENT AND TWO OF THE SQUAD THAT CAME!"

Aigis then came in from reviewing the footage of what has happened so far, and with a new naming system learned from her sister. But was there mostly to give Rise the nicknames and the call outs.

"In the first corner, it's the hometown heroes in training. You know them as the stars of class 1-A! It's Katsuki Bakugo!"

Katsuki then came out of one of the stadium door things, but had a spotlight thanks to Himiko.

"Or as according to this nickname, 'The Rage Tempered Bomb'!"

The crowd was then laughing at the nickname and at Katsuki for it fitting so well, Katsuki didn't have a good reaction to that.

"And also from Class 1-A, it's Shoto Todoroki!" And like before Shoto came out of the hallway thing.

"'The Half-Hot Half-Cold No Chill Ice'!"

And again, everyone was laughing at how it fit, but Shoto wasn't to visibly shaken.

"And from the corner of the visitors, it's Yasogami's Steel Council President, Labrys!"

Labrys came out from the other end, and the crowd was cheering, but a bit less with the giant she had. Labrys didn't care though, she waved back at the crowd.

"And Shizuka Shirogane: The 1000 I.Q. Orphaned Tomgirl Detective of Truth!"

Shizuka then came out, and the crowd roared at her arrival. She did a wave as a nice gesture, but looked at the two U.A. students with a serious gaze. Labrys did have a few problems after she failed to protect her, but she helped her to get over that. Now they had a fight.

"FINAL ROUND, FIGHT!"

And at that, the two teams attacked. Well… kinda, Team Persona did the only teamwork as they had partnership. As for Team U.A… not so much.

"Hey, what are you doing you hot cold bastard!?"

Shoto tried to use his ice to stop them, but it got in the way of Katsuki, so he smashed it. So Shoto made more ice to compensate, but it got in the way of Katsuki, so he smashed it. It's pretty clear that what's happening is a loop. So let's go to the point where Shizuka and Labrys are practically laughing at them.

"I'm trying to win, what are your doing?"

"I'm trying to win, but you keep getting in the way bastard!"

"Oh really? You're the one getting in my way!"

Labrys and Shizuka got over their laughing, and just smashed through the little ice there was.

"Azrael/Ariadne!"

With the two personas attacking, and the force of what was practically a tritium bomb. With the force of the enhanced light, darkness, and the physical attacks, Katsuki and Shoto were taken down with relative ease.

"Winners: Shizuka and Labrys!" and the crowd went wild.

* * *

 _Ok… done with this imagination, I'm going to continue work on Tekken x MHA_


End file.
